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Results from HiRes and Observation of the GZK Suppression

Results from HiRes and Observation of the GZK Suppression. HR2. HR1. Kai Martens High Energy Astrophysics Institute Department of Physics, University of Utah for the HiRes Collaboration. Outline:. Short Introduction to Cosmic Rays The HiRes Experiment Monocular Observation:

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Results from HiRes and Observation of the GZK Suppression

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  1. Results from HiResand Observation of the GZK Suppression HR2 HR1 Kai Martens High Energy Astrophysics Institute Department of Physics, University of Utah for the HiRes Collaboration

  2. Outline: • Short Introduction to Cosmic Rays • The HiRes Experiment • Monocular Observation: • Going to Extremes • Evidence for GZK Suppression • Stereo Observation: • Checks and Balances • HiRes Composition Measurement • Interpretation: • Ankle, Cutoff, and Cosmogenic Neutrinos • HiRes Neutrino Limits • In Search of the Sources: • Anisotropy • Correlations • Conclusions Kai Martens, University of Utah, @ ISMD

  3. Cosmic Rays 102 Swordy Plot: knee Power laws for Flux: J~Eg <3 PeV: g=2.7 ~3 PeV: Knee >3 PeV: g=3.0 (m2 sr s GeV)-1 ankle / 1 km2 y 10-28 GeV TeV PeV EeV Kai Martens, University of Utah, @ ISMD

  4. Air Shower Dimensions • Cosmic Ray showers • start at ~ 15 km above ground • span a couple of km across • hundreds of billions of particles 1019 eV Fluorescence Detector: longitudinal profile throughout atmosphere Ground Array: transverse profile at ground level thick water tanks  thin scintillators (e/m + m) (e/m only) Kai Martens, University of Utah, @ ISMD

  5. The HiRes Experiment: Delta HiRes on DPG: HR1: 5/1997 19 mirrors 3-17elevation Sample&Hold HR2: 12/1999 42 mirrors 3-31 elevation FADC (100ns) Dugway Proving Grounds 12.6 km apart Kai Martens, University of Utah, @ ISMD

  6. HiRes Optics: SUN: ½o low resolution high speed Camera: 16 x 16 PMT each sees 1o x 1o in sky Mirror surface 5.1 m2 Field of view: 16 x 14 UV filter !!! (protecting PMTs) Kai Martens, University of Utah, @ ISMD

  7. HiRes: Stereo!!! July 11, 1999; Energy: 19 EeV Light Propagation: Atmosphere HR1 HR1 HR2 Dugway Proving Ground HR2 Kai Martens, University of Utah, @ ISMD

  8. The Collaboration: S. BenZvi, J. Boyer, B. Connolly, C.B. Finley, B. Knapp, E.J. Mannel, A. O’Neill, M. Seman, S. Westerhoff Columbia University J.F. Amman, M.D. Cooper, C.M. Hoffman, M.H. Holzscheiter, C.A. Painter, J.S. Sarracino, G. Sinnis, T.N. Thompson, D. Tupa Los Alamos National Laboratory J. Belz, M. Kirn University of Montana J.A.J. Matthews, M. Roberts University of New Mexico D.R. Bergman, G. Hughes, D. Ivanov, L. Perera, S.R. Schnetzer, L. Scott, S. Stratton, G.B. Thomson, A. Zech Rutgers University N. Manago, M. Sasaki University of Tokyo R.U. Abbasi, T. Abu-Zayyad, G. Archbold, K. Belov, A. Blake, O. Brusova, Z. Cao, W. Deng, W. Hanlon, P. Huentemeyer, C.C.H. Jui, E.C. Loh, K. Martens, J.N. Matthews, D. Rodriguez, K. Reil, J. Smith, P. Sokolsky, R.W. Springer, B.T. Stokes, S.B. Thomas, L. Wiencke University of Utah Z. Cao, B. Zhang, Y. Zhang, Y. Yang IHEP Bejing Kai Martens, University of Utah, @ ISMD

  9. Challenge: (Mono) Reconstruction Time (100 ns) Photoelectrons at detector  Time to common stop  amount of matter (air) traversed  angle above horizon  angle in plane  In-plane Angle (deg) angle along horizon  Reconstruction steps: 1. shower detector plane 2. Shower axis (full geometry) 3. fluorescence light curve (FADC !!!) light curve + atmosphere = energy Kai Martens, University of Utah, @ ISMD

  10. HiRes Monocular Spectra HR1: longer exposure  high energy HR2: larger elevation coverage  low energy data: HR1: 5/97-6/05 HR2: 12/99-8/04 • energy scale uncertainties: • missing energy 5% • energy loss rate 10% • fluorescence yield 6% • atmospheric conditions 4% • photometric calibration 10% • total (energy): 17% •  flux uncertainty: 30% (@ g=2.8) flux x E3 Kai Martens, University of Utah, @ ISMD

  11. HR1: Aperture Verification - Data vs. MC Kai Martens, University of Utah, @ ISMD

  12. HR2: Aperture Verification - Data vs. MC Kai Martens, University of Utah, @ ISMD

  13. GZK Suppression: ? !! avoid double counting: remove HR1 events that also are in the HR2 data set Old plots: AGASA AGASA (E–20%) Broken power-law fits: a.) one vs. two breakpoints: 2 reduced by 23.4  4.5s b.) compare measured data to red line extrapolation: expect: 39.9 observe: 13  4.8s (P=7x10-7) Quacks like duck, don’t it? Kai Martens, University of Utah, @ ISMD

  14. Stereo Observation stereo advantages: geometry constraint (!!!), light balance check on atmosphere full stereo analysis ongoing; shown: geometry from HR1/HR2plane intersect, light curve from HR2 data only: energy balance: Xmax resolution: 30g/mc2 Kai Martens, University of Utah, @ ISMD

  15. Composition from Stereo Data Xmax distributions: MC: p data vs. proton Xmax [g/cm2] data: HR prototype MC: Fe HiRes stereo data: ~ 80% p data vs. iron Fe + p  |  (mostly) p 18 20 log10(E/eV) galactic extra-galactic Xmax [g/cm2] Kai Martens, University of Utah, @ ISMD

  16. Interpretation of HiRes monocular CR: changed interpretation of ankle: Doug Bergman, Rutgers (following Berezinsky) p+g p+e++e-  redshift flux  Fit interprets spectrum in terms of extragalactic protons that traveled from cosmological sources propagation: protons only p+gD(1232) p+N p m + nm m  e + ne + nm energy  galactic/extragalactic transition: composition change vs.slope change composition change slope change Kai Martens, University of Utah, @ ISMD

  17. HiRes Composition Guided Fits n flux • source model: all sources inject with Eg • g = 2.42 • uniform with redshift • evolution (1+z)m • m = 2.46 composition as measured ! future: astronomy inspired redshift evolution Kai Martens, University of Utah, @ ISMD

  18. The HiRes Neutrino Limits: n event distinguishing features: - horizontal !!! - close to ground MC injection: E-2 spectrum 90% CL, uncertainty MC statistics only n fluxes as derived from HR spectrum fit nt limits: 1018 – 1019: 420-20+25 1019 – 1020: 1340-110+140 1020 – 1021: 29400-8900+22100 ne limits (no topography): 1018 – 1019: 3820 ±120 1019 – 1020: 3260 ±80 1020 – 1021: 4250 ±100 target mass: rock detector volume: air ne LPM nt t-lepton Kai Martens, University of Utah, @ ISMD

  19. MC: Topology at Work Cedar Mtns Stansbury Mtns Oquirrh Mtns Deep Creek Rng Sheeprock Mtns Fish Springs Rng Thomas Rng nt interaction points for t decaying above ground: t zenith angle in HR system: 90 95 Kai Martens, University of Utah, @ ISMD

  20. Anisotropy and Clustering HR2 Sky Map: • non-uniform exposure… use MC & on-time database to estimate uniform exposure • Findings: • no global dipole • deficit at Galactic Anticenter??? (3.4s) Looking for Accelerators: BL lac Tinyakov, Tkachev, Gorbunov analysis: Vernon 9th, m<18, AGASA+Yakutsk: E>48 (24) EeV  P=10-4 Vernon 10th, BL criteria differ, HiRes: E>10 EeV P=10-3 HiRes analysis (all events): 0.02%  the jury is still out: more data Point Sources: AGASA for E > 40 EeV: 5 doublets, 1 triplet HiRes stereo +AGASA: 28% of MC > triplet HiRes: E > 30 EeV:  triplet + 1 Kai Martens, University of Utah, @ ISMD

  21. Fixed Target Experiment @ 31018eV HiRes 2007 HiRes: Data: mean energy: ~ 1018.5 eV “protons” selected Xmax Kai Martens, University of Utah, @ ISMD

  22. Now Commissioning: Telescope Array 512 x 3m2 scintillator array A T MCCRC Delta, UT 2h from SLC 3 x 120 deg fluorescence telescopes Kai Martens, University of Utah, @ ISMD

  23. Conclusions • HiRes has finished taking data • HiRes has changed the cosmic ray (CR) landscape: • - extragalactic CR mostly protons • - GZK suppression present in data  D+ resonance • ankle likely e+e-, not transition to extragalactic… •  spectral features important  TALE • HiRes finds no significant UHE-CR anisotropies • HiRes finds no significant UHE-CR clustering • Correlations with astrophysical sources: jury still out • Ultra High Energy (UHE) CR research is alive in Utah: • Come and join our efforts for TA/TALE www.telescopearray.org kai@physics.utah.edu Kai Martens, University of Utah, @ ISMD

  24. HiRes & Auger Limits Kai Martens, University of Utah, @ ISMD

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